Feature/docs (#165)

* initial readthedocs commit

* docs moved to sphinx / rst / read the docs

docs/features/authentication.rst

@@ -0,0 +1,42 @@
+Authentication
+==============
+
+Users register authentication services in their Startup.cs as usual but they provide a scheme (key) with each registration e.g.
+
+.. code-block:: csharp
+
+    public void ConfigureServices(IServiceCollection services)
+    {
+        services.AddAuthentication()
+            .AddJwtBearer("TestKey", x =>
+            {
+                x.Authority = "test";
+                x.Audience = "test";
+            });
+
+        services.AddOcelot(Configuration);
+    }
+
+
+In this example TestKey is the scheme tha this provider has been registered with.
+We then map this to a ReRoute in the configuration e.g.
+
+.. code-block:: json
+
+    "ReRoutes": [{
+            "DownstreamPathTemplate": "/",
+            "UpstreamPathTemplate": "/",
+            "UpstreamHttpMethod": ["Post"],
+            "ReRouteIsCaseSensitive": false,
+            "DownstreamScheme": "http",
+            "DownstreamHost": "localhost",
+            "DownstreamPort": 51876,
+            "AuthenticationOptions": {
+                "AuthenticationProviderKey": "TestKey",
+                "AllowedScopes": []
+            }
+        }]
+
+When Ocelot runs it will look at this ReRoutes AuthenticationOptions.AuthenticationProviderKey 
+and check that there is an Authentication provider registered with the given key. If there isn't then Ocelot 
+will not start up, if there is then the ReRoute will use that provider when it executes.